I layer tender potato slices with savory French onion soup mix, caramelized onions, garlic, and a splash of broth, then bake everything until the potatoes are melting soft and the top is golden and irresistible.

Why I’ll Love This Recipe

I adore how this bake combines the cozy flavors of French onion soup and potatoes into one easy-to-make casserole. Minimal prep—just slice, toss, and bake—and it delivers deep oniony sweetness, comforting starchiness, and a bit of cheesy luxury if you choose. Perfect for busy nights or holiday spreads

ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

White potatoes (Russet or Yukon Gold), peeled or unpeeled
Yellow or brown onions, thinly sliced
Garlic, thinly sliced (optional)
French onion soup mix (dry mix and/or canned French onion soup)
Unsalted butter or olive oil
Hot broth or water
Fresh rosemary or thyme sprigs
Optional: shredded Gruyère, Swiss, or Parmesan cheese
Salt & pepper

directions

Preheat oven to ~375–400 °F (190–200 °C).
Slice potatoes into even ¼‑inch rounds. In a large bowl, toss them with melted butter or oil, garlic (if using), and the French onion soup mix. Add hot water or broth just enough to coat and moisten
Spread the potato mixture in a greased casserole dish. Nestle rosemary or thyme sprigs on top.
Cover with foil and bake for ~30 minutes, then uncover and bake another 30 minutes—stirring once halfway—until potatoes are tender and most liquid is absorbed .
Sprinkle cheese over the top (if using) and return to oven uncovered for 10–15 minutes until cheese is melted and golden .
Remove from oven and let rest 5–10 minutes to set before serving.

Servings and timing

Serves: 6–8
Prep time: ~15 minutes
Cook time: ~60 minutes (covered + uncovered baking)
Total time: ~1 hour 15 minutes

Variations

Creamy upgrade: Swap water for broth or add cream and cheese to layer for a richer gratin-style bake .
Cheesy top: Finish with Gruyère, Swiss, or Parmesan for a melty, flavorful crust .
Herb blends: Use thyme or Italian seasoning if rosemary isn’t available
Fully French-style boulangère: Layer onions and potatoes without cheese or cream, cooking slowly in broth for a leaner version
Add protein: Stir in diced ham or cooked bacon for extra heartiness .

storage/reheating

I cool leftovers, cover tightly, and store in the fridge for up to 4 days. To reheat, I cover with foil and warm in a 350 °F oven until heated through—about 15–20 minutes. Freezing is also allowed: thaw in fridge, then reheat same way for best texture.

FAQs

Can I prep this ahead of time?

Yes—I assemble the potato mixture in advance, cover, and refrigerate. I bake covered, then finish baking just before serving .

What if I don’t have French onion soup mix?

You can use a packet of onion soup and add dried garlic, salt, and herbs to mimic the flavor—just mix it into the tossed potatoes.

How do I prevent soggy bake?

Make sure to uncover halfway through baking so excess liquid evaporates, and stir once to redistribute moisture .

Can I make it dairy-free?

Yes—use olive oil instead of butter and omit cheese, or sprinkle nutritional yeast for cheesy flavor without dairy.

What pairs well with this dish?

I enjoy it alongside roast chicken, grilled steak, or baked salmon—its savory richness complements protein dishes perfectly

Conclusion

I absolutely love this Easy French Onion Potato Bake—it’s cozy, easy, and endlessly adaptable. Every bite brings caramelized onion flavor, juicy potatoes, melty top, and aromatic herbs. It’s my go-to side dish for weeknight dinners, holiday feasts, or anytime I crave satisfying comfort food without the fuss.